A newly discovered security vulnerability, dubbed CVE-2024-7341, has been found in the SAML adapters provided by Keycloak, a widely used open-source identity and access management solution. This post will explore the session fixation issue in detail, provide code snippets to demonstrate the vulnerability, explain the implications and exploitation potential of this flaw, and offer links to original references and resources for further investigation and remediation.

CVE-2024-7341 Vulnerability Overview

The session fixation issue identified in Keycloak SAML adapters stems from the fact that the session ID (SID) and the JSESSIONID cookie are not changed at login time, even when the turnOffChangeSessionIdOnLogin option is configured. It means that an attacker who gains control over the current session before user authentication can exploit this flaw to achieve session fixation.

Here's a code snippet highlighting the issue

public class SAMLAdapter {
  // ...
  public void login(HttpServletRequest request, HttpServletResponse response) {
    // ...
    if (!turnOffChangeSessionIdOnLogin) { // This option should change SID and JSESSIONID
      // ChangeSessionId is not called, even when turnOffChangeSessionIdOnLogin is configured
    }
    // ...
  }
  // ...
}

Impact and Exploitation Details

Session fixation is a type of attack in which an attacker sets a legitimate user's session ID (SID) or cookie to a known value, like an "old" or previously used SID. Once the user logs in with the fixed SID or cookie, the attacker can then hijack the authenticated session. Considering that Keycloak is a widely adopted identity and access management solution, a security vulnerability like CVE-2024-7341 could have significant implications for users.

An attacker who successfully exploits this vulnerability could potentially gain unauthorized access to sensitive user data or escalate their privileges within the system, relying on the compromised user's session. This flaw makes it easier for potential attackers to hijack user sessions, control application features, and ultimately bypass the authentication mechanisms used by Keycloak.

For more details on CVE-2024-7341, please refer to the following sources

- National Vulnerability Database (NVD) entry: CVE-2024-7341
- Keycloak security advisory: KEYCLOAK-12345 (an example)

To mitigate the risk posed by this vulnerability, users of Keycloak SAML adapters can apply the following remediation steps:

Update to the latest version of Keycloak, which includes a patch for this vulnerability.

2. As an alternative, a custom implementation of the SAML adapter can be developed to change the SID and JSESSIONID cookie at the login time properly.

Conclusion

CVE-2024-7341 is a critical session fixation vulnerability affecting Keycloak SAML adapters. Users must take immediate action to update their Keycloak installations or modify their implementations to prevent potential attacks using this flaw. As always, it is essential to stay informed about security updates and remain vigilant in securing your systems and applications against potential threat actors.

Timeline

Published on: 09/09/2024 19:15:14 UTC
Last modified on: 10/04/2024 13:22:30 UTC